Synthesis and Properties of Composites Based on Zirconium and Chromium Borides

Autor: Yu. N. Barinov, V. A. Shcherbakov, O. I. Botvina, A. N. Gryadunov
Rok vydání: 2019
Předmět:
Zdroj: Russian Journal of Non-Ferrous Metals. 60:179-185
ISSN: 1934-970X
1067-8212
DOI: 10.3103/s1067821219020135
Popis: Experimental data on the fabrication of composites based on the ZrB2–CrB system by SHS compaction are presented. Adiabatic combustion temperatures of the Zr–Cr–B system and compositions of equilibrium synthesis products are calculated using the thermodynamic data, and optimal fabrication conditions for SHS composite production are determined. It is shown that the equilibrium synthesis products are ZrB2 and CrB refractory compounds. They provide the high thermodynamic stability of SHS composites, which are applied as a dispersed phase (ZrB2) and ceramic binder (CrB). The adiabatic combustion temperature decreases from 3320 to 2350 K with an increase in the binder content from 25 to 64 wt %. A hard dispersed phase (ZrB2) and molten binder (CrB) are formed under these conditions. It is revealed that the formation of a molten binder provides the formation of SHS composites with residual porosity lower than 1%. The influence of the composition of the reaction mixture on the phase composition, microstructure, and physicomechanical characteristics of SHS composites are investigated. It is established that the residual porosity at the CrB content in the limits of 30–50 wt % is
Databáze: OpenAIRE
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